Devices for producing and controlling airflow around airfoils



March 20, 1962 c. H. GRANT DEVICES FDR PRoDUcING AND CDNTROLLING AIRFLOW AROUND AlRFoILs 4 Sheets-Sheet l.

Filed Nov. 13, 1957 March 20, 1962 Filed Nov. 13, 1957 C. H. GRANT DEVICES FOR PRODUCING AND CONTROLLING AIRFLOW AROUND AlRFOILS 4 Sheets-Sheet 2 March 20, 1962 c. H. GRANT DEVICES FOR PRoDUcING AND CONTROLLING AIRF'LOW AROUND AlRF'OILS 4 Sheets-Sheet 3 Filed NOV. 13, 1957 March 20, 1962 c. H. c; N

DEVICES FOR PRODUCING AND CONTROLLING AIRFLOW AROUND AlRFoILS 4 Sheecs-Sheet 4 Filed Nov. 13, 1957 United States Patent 3,026,067 DEVICES FR PRGDUCING AND CONTROLLING AIRFLOW AROUND AIRFOLS Charles H. Grant, 166 Centre Ave., New Rochelle, N.Y. Filed Nov. 13, 1957, Ser. No. 696,107 28 Claims. (Cl. 244-42) This device relates to aircraft and to means for increasing their lifting capacity and control. The improvements are directed to airow control members'of an airplane known as airfoil nose shrouds, airow deflectors and directors and air ducts, with means for operating moveable members separately or in conjunction with each other and other members of the aircraft.

ln general, it is the purpose of this device to direct, regulate and otherwise control `the airow around airfoils, particularly that part of such ow adjacent to their surfaces, known as the boundary layer.

More specifically it is the purpose of this device to increase the lifting capacity of an airfoil to which it is applied, by providing, engaging and directing an increased volume of airflow against and around said airfoil at higher velocities and at larger upward angles of approach than those characteristic of said typical airfoils without such airflow directing means.

lt is also a specific purpose of this invention to prevent, reduce or otherwise control the chordwise movement of the center of pressure.

For example when it is used in combination with a trailing edge ap, it prevents the center of pressure from moving rearward which is the usual result of flap depression in the case of conventional flapped wings. It achieves this effect by increasing the lift over the forward portion of the wing to compensate for the increase in lift over the rearward portion due to flap action, thus reducing pitching moments resulting from rearward movement of the center of pressure. This feature eliminates a hazard to vertical take-o and improves the overall performance of the plane considerably.

Therefore this device includes the use of its numerous or single features in combination and/or in conjunction with trailing-edge aps so-called.

Another purpose is the regulation and control of lift, increasing or decreasing it at will, by regulating airflow through changing the relative position and angles of surfaces, auxiliary to the wings and other airfoils Yof the aircraft. n such instances these auxiliary surfaces may or may not constitute part of the airfoil itself. Through these means the spanwise as well as the chordwise position of the center of lift on the wing may be changed by control action not only to keep it from moving rearward, but also to regulate and control both its chordwise and spanwise position.

One particular objective of this invention is to provide substantial lift without forward motion of the aircraft by using airow producng means such as a propeller fan or jet stream, and which is situated suitably to direct airflow against an airfoil that embodies the device or elements of it. Thus this device in effect includes the combination of airflow producing means with auxiliary airflow control surfaces that are associated with a lifting airfoil surface.

Therefore the primary purpose of this device is to increase the lift of wings of an aircraft for vertical rising and descent and for shortening take off run, or to control the aircraft, laterally, longitudinally and directionally, through regulation of airflow and pressure over suitable control surfaces.

An example of the application of this device for lateral control is the pivoted and movable shroud members forward and above the leading edge of the wing. The volume and velocity of arow over the wing may be 3,026,067 Patented Mar. 20, 1962 regulated by changing the angle of these shroud members relative to the wing.

By connecting the shrouds on the left `and right wing through controls so the angle of one is increased when that of the other is decreased, simultaneous lift differentials on the right and left wings can be obtained to produce rolling moments either to the right or to the left. Thus they serve as leading-edge ailerons.

By moving the shrouds in like manner on both wings their lifting eect may be controlled and thereby the wing center of pressure movement can be controlled.

By increasing the lift due to the nose shroud, the rearward center of pressure movement is reduced or entirely eliminated. It is possible in fact in this way to cause the center of pressure to move forward.

Conversely, by decreasing the lift resulting from the shroud angle, the rearward movement of the center of pressure can be increased. Thus this movement may be controlled through shroud manipulation by the pilot through suitable controls, and aircraft trim and balance thereby may be conveniently maintained.

This device may be applied elfectively also to airfoil surfaces of Ithe tail group, to aircraft wings or to any other such surfaces to increase their aerodynamic elect.

When applied to aircraft wings, it lincreases lift so smaller wings may normally be used, or take off, landing and even level flight speeds may be materially decreased to serve useful purposes.

By situating the Wings of an aircraft with the device eectively in the slipstream of the aircrafts propeller, or in airow resulting from other means such as a jet engine, lift can result without forward motion of the aircraft. My invention increases this lift to such an extent that the aircraft will require little, if any, forward motion to rise.

When applied to the tail surfaces, the propeller slipstream or other airflow producing means likewise can be made to provide effective control without forward motion of the aircraft. This is most important in vertical rising aircraft where no airow over the tail control surfaces results from forward motion. Y

Other purposes, applications and advantages will hereinafter appear.

Basically this device comprises an airfoil in combination with means for generating and/or engaging and directing airflow against the leading edge of said airfoil and over its surfaces.v This airow may originate from a revolving aircraft propeller, from a fan, blower, the air compressor, or jet stream of a jet engine, or merely from the forward motion of the aircraft embodying this combination.

In a simple form it comprises an airfoil or wing, with or without a trailing edge ap, in combination with smaller spanwise leading edge airfoil members for guiding arflow over the larger airfoil or wing.

ln this arrangement the leading edge members comprise an upper shroud member and lower deflector members. ln extended positions for high lift the shroud is situated above the wing chord line substantially forward of and in spaced relation to the airfoil or wing leading edge. Then the deector members are situated below the said chord line and at greater negative angles of incidence than the shroud, so that the passageway between the shroud and large deflector converges from their leading to trailing edges. There may or may not be space for air passage between the larger deector member and the wing.

Thus the shroud and dellector in combination form a rearwardly converging passageway or venturi that engages, and directs approaching airflow against and over the more rearward airfoil or wing at an increased angle of attack,

at greater velQCity and Vin greater volume, which all re- Ysults in considerable increase in lift.

The amount of this lift increase is dependent largely upon the volume o f airnow-:sodirected over the airfoil or wing. Consequently one of the essential and novelV features of `this invention is .the large size of therventuri passageway'entrance between the leading edges of shroud and deilector. .This entrance opening is much larger than the maximum thickness of the more rearward airfoil or wing and therefore engages and directs a much larger volume of air over .the wing than otherwise would be the Case- Also, the velocity of this ow is increased bythe converging venturi passageway formed by these elements and the upward angle of how-approach is increased by the deector elements which divert a large amount of the approaching ow upward from below the wing.

The deector may assume several different forms. One lthat is an important feature .of this device comprises two deflector elements, a large forward deflector 3 and a smaller, lower, and more rearward element hereinafter called `a reflector 4 (FIGURES 7710). Above the larger detlectorV is a passageway for airflow that is redeflected downward behind the larger element by the smaller rearward reiiector element. A large part of the airflow that otherwise passes rearward beneath the larger deiiector and wing, thereby is interrupted,jretarded, and diverted upward in front of the defiector and over the upper suryface pf the wing.

VThis increases the effectiveness of the deflector and wing to result in greater lift.

Under some circumstances structural and control considerations may require the upper shroud member and the lower large deflector member to be formed together as an integral unit ,such as an elongated spanwise duct fbrward of the leading edge of the airfoil as applied to `taila'irfoil surfaces, FIGS. l, 2, and 5. In such cases the duct is`also` elongatedl to yextend forward through the fuselage or other parts of the aircraft so its forward opening is immediately rearward of the propeller or other flow producing means. This then servesto conduct part of the resulting niiow rearward andover the control surfaces.

When appliedV to ythe leading edges of airplane wings, FIGS. '1, 2, 3` and 4, shroud and Ydeliector members are substantially separate and of comparatively short chord. However, this is not intended to be a limiting specification of ,the device because these two members may be spaced, relative to ,their adjacent sur-faces, but connected chordwise at their spanwise ends, FIG. 8.

Also included as anoptional feature of this device is a propelleror Vother means situated to provide and direct airow against a wing leading edge that mounts shroud and deflector components of the device, so that at least pats of this flow pass around and by` this wing assembly as Well as other aufoil surfaces that may be situated rearward thereof,irrespective of `whether or not the aircraft has forward motion.

Y"Such ow producing means may constitute the air compresser or the jet stream of 'a jet engine, or a fan or blower situated kto produceflow against and around an airfoil. An example of such a fan driven by the aircraft engine through connecting means, is shown in the airduct lthat leads to the horizontal control surfaces of an aircraft, FIG. 2. a

Another important feature of this invention is the vertical panels at the outboard ends of the high lift wing panel'directly rearward of the propeller. These vertical members guide and direct the propeller slipstream and/ or other flow over the high lift wing panel to obtain maximum effect. v

Vertical panels also are attached to the ends of the Hap panels FIG. 8, and prevent the airow beneath the flaps from spillingl out sideways with resulting loss of lift when the aps are depressed.

Through these and other means this device produces lift by propeller slipstream action and other induced airow, on the aircraft wing surfaces, and provides control by parts of said slipstream or airow acting also on suitable control surfaces such as ailerons, elevons, rudders, and movable shroud members when the airplane has no forward movement.

Lift on saidl wings necessarily .must be considerable and greater than the weight of the aircraft in order to cause the aircraft to rise. My device consequently is new and important because it substantially increases the normally resulting lift of an airfoil whether airflow results from forward iiight alone, from propeller slipstream or other tiow. Thus, capabilities of vertical flight with power are increased, as well as slower landing ight without power.

In the application of my invention to the leading edge of a wing, FIGS. l, 2, 3, 4 and 5, it is foreseen that the shroud member 2 and/or deector member 3 may be either xedly attached to the wing member 1, in extended predetermined spaced interrelation, or attached to provide restrained controlled movement into numerous prescribed interrelated positions. When these shroud and deilector members are movable, Ythey may assume either extended positions for increased life or closed positions to form in combination with the wing member, a single airfoil with prescribed adequate and relatively continuous contours for high speed. Also these members, when movable, may be designed either for adjustment into fixed positions by hand on the groundor for movement into various positions as desired for control of the aircraft during ight and on the ground, through the operation of controls' by the pilot, BIG. 6,.

It is foreseen that rearward flap members may or may not be used in combination with the forward shroud and deector members. When flaps are so used, it is conceived lthat this invention Shall include the operation of the flap and forward members in various combinations of relative .movement through control operation.

Therefore, controls may include'rneans for operating either-the forward members or the Hap members separately or both simultaneously through separate controls for each group of members, FIG. l6, and also for operating all members simultaneously in conjunction with one another through a single interconnected means of control, FIGS. 3 and 4.

Controls may also include the means to adjust and regulate the extent of controlled movement of either the pilaps, shroud or deector, relative to one another and t0 the aircraft.

' It is intended that these operating and adjusting means may constitute either mechanical, hydraulic, electrical or pneumatic devices or combinations thereof. FIG. 6 shows a plan view of such typical mechanical means. This means is not necessarily limited to one clutch as shown. Both shroud and ap controls may be so equipped.

'In the accompanying drawings illustrating this device:

FIG. 1 is a sideview of my device applied to a suitable airplane and which shows a chordwise sectional view of the wing and horizontal tailplanes with the shroud, deflector, flap and tail airduct members extended for maximum lift effects. The section is taken on the plane 1 1, indicated in the plan view, FIG. 5.

FIG. 2 is a similar sideview ofthe invention showing a section on the plane 1-,1 of FIG. 5, through thewing and tail planes with the shroud, deflector, ap and tail airduct group members retracted forV horizontal and high speed flight.

FIGS. 3 and 4 are sectional views showing one form of the device applied to a wing and details of one application of interconnected control mechanism.V FIG. 3 shows elements in extended position for high lift. FIG. 4 shows them retracted for high speed.

FIG. 5 is a plan View of an airplane with ya form of this device applied to the center wing panels and the lower stabilizer with elevons for control.

FIG. 6 illustrates typical mechanical control means for operating the nose members and ap members either separately or in conjunction with one another.

FIG. 7 shows my wing devices including ya pivoted non-retractable shroud element with controls for varying and for regulating its angle of incidence: Large deflector with flow channel and auxiliary flow reflector is also shown.

FIG. 8 is a perspective view of a modified construction of the Wing panel including retractable nose elements and flap in extended positions with vertical chordwise guide panels on rigid wing portion and depressed flap.

FIG. 9 shows a section of a wing with retractable nose elements orr this invention in extended position, operating mechanism, control elements for extending these elements and control mechmsm for changing the angle of incidence of the pivoted shroud elements.

FIG. l shows the same mechanism and arrangement as FIG. 9 with nose elements in retracted positions.

FIGURE ll is a fragmentary perspective view showing a portion of the link-operating mechanism illustrated in FIGURES 9 and 10.

Throughout the specification and drawings, similar reference characters represent corresponding parts.

Referring to the accompanying drawings for a detailed description of one form of embodiment of my invention, the numeral 1 designates the rigid Wing structure of an airplane at the forward part of which is mounted a nose shroud 2 and a deliector 3 below it. When the nose shroud 2 and the deflector 3 are in extended positions, as will be hereinafter explained, they form a duct for bringing in a large volume of air to the wing structure 1 which is situated more rearward than the shroud 2 and deliector 3. A smaller element, reflector 4 is below and behind deector 3. A typical flap and auxiliary hinged gate assembly 5 with slot controller 6 are mounted at the rearward part of wing structure 1. FIGS. 4 and 10 show movable elements retracted. FIGS. 3, 5, 7, 8, and 9 show them extended.

This Whole wing combination is mounted effectively as a wing panel in the slipstream flow produced by rotating propeller 7. This wing panel is bounded at its outboard ends by chordwise vertical panels 8, fixed to the rigid wing structure 1, and panels 9 fixed to the ends of the flaps. These restrain and guide the slipstream flow across the wing panel, FIG. 8.

Shroud 2 is attached to bracket 10, FIGS. 7, 8, 9 and l0, with illustrate controllable shrouds, or directly to bracket 11, FIGS. 3 and 4, when shroud 2 is rigidly attached.

Bracket 1t) is pivotally attached to bracket 12 at pivot 13. Both brackets 11 and 12 with shroud are pivotally attached to bracket arms 14 and 15 at points 16 and 17 which in turn are pivotally fastened to the rigid Wing structure 1 at points 18 and 19.

In FIG. 7 showing a permanently extended shroud the bracket 11 is xedly attached to the rigid wing structure 1. As in FIG. 7, the control rod is attached to bracket 10 at pivot 21 and to the control arm 22 at pivot 23. The control arm 22 is attached to control shaft 24 and turns With it.

In FIGS. 8, 9 and l0 the rear end of rod 20 is connected to control lever 25 at pivot 26 which is behind and in line with pivot 17. Control link 27 is connected to control lever 25 at point 28, directly behind pivot 19 and to control arm 22 at point 23. The control lever is pivoted at 25A to the bracket arm 15. A detail of this link mechanism is shown in FIGURE ll.

The large deflector 3 and the smaller reflector 4 are mounted rigidly on bracket 30, pivoted to the rigid wing structure 1 at 31. Link 32 connects the deflector assembly to the shroud bracket 11 in FIGS. 3 and 4 and to bracket 15 in FIGS. 8, 9 and l0. Ends of link 32 are pivoted to the detiector bracket at 33 and to the shroud brackets 11 or 12 or to bracket arm 15 at point 34.

Forward operating link 35 connects the shroud and/or deector assembly to the master control `arm 36; pivoted to the shroud brackets 11 or 12 at 17 and to the control bracket at 37 except where rigidly attached shrouds are used as in FIG. 7 in which case operating link 35 is attached directly to the deector assembly at 33.

Flap 5 is connected to the rigid wing structure through brackets 38 and 39 at point 40. Slot controller 6 is pivoted to the wing at 41 and is connected to the flap assembly by link `42 which is pivoted to the controller 6 at point 43 and to the flap bracket 33 at point 44.

Rear control link 45 is pivoted to the ap control arm 46 at 4.7 and connects rit to the master control arm 36 at point 48. Flap operating link 45A is connected to the rear control link 45 at pivot 47 and to the ap at 47A. The control arm 36 is mounted on control shaft 49 and rotates with it in response to pilot control action transmitted through 49.

Through connection to the common unit, arm 36, shroud 2, dcflector 3, reliector 4, flap 5 and controller 6 operate simultaneously and in coordination with one another.

In the case of a rigid shroud, FIG. 7, only defiector 3 and reflector 4 operate simultaneously and in coordination with thetrailing edge flap elements 5 through common attachment to arm 36. Angular movement of the shroud is achieved through separate control mechanism including control rod 20, control arm 22 and shaft 24.

When control arm 36 is in extreme counter-clockwise position (as viewed in FIG. 4 and l0), shroud, deflector, flap and slot controller are in retracted position for high speed flight. When arm 36 is rotated clockwise, as illustrated in FIG. 3, 7 and 9, all these said wing elements are moved to extended positions for flight conditions requiring high lift.

Throughout this extending movement, the actions of deflector 3, reector 4 and shroud 2 are simultaneous and coordinated by means of their interconnecting link 32 except when a fixed shroud 2 is used, and the actions of flap 5 assembly and controller 6 are simultaneous and are coordinated by means of interconnecting link 42.

Hole 50 near end of rear control link 45, FIG. 3, represents a means for attaching link 45 to bracket 36 at hole 51 for reduced movement of link 45 and resulting reduced deflection of flap 5 and controller 6, relative to the extended movement of forward elements, shroud 2, deector 3 and reflector 4. Likewise, extension of the forward elements by control action may be reduced relative to the flap and controller deflection by attaching the forward link 35 at hole 52 to the control bracket 36 at hole 53.

FIG. 6 illustrates a control mechanism by which either `the forward shroud and deliector or the rearward ap assembly with slot controller may be operated independently or in conjunction with one another.

Forward operating links 35 connect the nose elements to master control arm 36-S which in turn is xedly mounted on shaft 49.

The flap operating links 45 connect the ap elements to master control arm 36-F which in turn is fixedly mounted on a tubular sleeve on shaft 49, which sleeve is free to rotate on shaft 4g when the flap is operated alone and separately from the nose elements. (In FIGS. 9 and l0, master control arm is one unit and not two separate operating units as in FIG. 6.)

The lower crosshatched mechanism is a section of the housing SS-AH which encloses a worm wheel 55-G attached on a tubular sleeve on and around shaft 49. This wheel SS-G is engaged with and turned by a Worm 55-W on shaft 55-S. On the right-hand end of shaft 55-S is bevel gear 55-B1 engaged with another bevel gear 55-B2, on a shaft 55-A2 which is perpendicular to the worm shaft SS-S. On this shaft is a clutch 54 shown 1n disengaged position. Shaft 55-A is divided into two portions, 55eA1 and SS-AZ, each free to turn independently of one another when the lower half 54A of splined clutch S4 is disengaged from the upper half 54-B; the lower half 54-A being attached iixedly in a rotational sense relative to the lower portionV 55A2 of shaft 55-A, but free to slide alongla splined end of portion 55-A2 of the shaft so it may engage the adjacent half 54-B of the clutch 54 that is attached rigidly to the upper portion 55-A1 of shaft 55-A. This movement of the lower half of the clutch is accomplished through shaft 56 and the yoke 56-Y which operates the lower half 54-A of clutch 5a.. Moving shaft 56 axially upward moves clutch half 54-A upward into engaged relation to the fixed upper half SLi-B. Moving shaft 56 downward andtparallel to shaft Stil-A, disengages the two clutch halves aftertengagernent.

Both or either one of shafts 55 and 55-A extend to operating means in the cockpit and the mechanism may be operated through either shaft 55 or SS-A, or through both.

Shaft 55 is connected to shaft SS-A through spur gears 55#P and 55AP. Shaft 55, therefore, always turns simultaneously with the upper half 55A1 of shaft SS-A. Shaft 55 is connected to shaft 49 through bevel gears, worm, and worm wheel mechanism SS-H, similar to the mechanism SS-AH shown cut away and crosshatched. However, the worm wheel of this mechanism SS-AH is mounted iixedly on the tubular sleeve that, in turn, is mounted on shaft 49. The arm 36-F for ap operation, which is mounted fixedly on this sleeve, turns with it when shaft SS-A turns and clutch 54 halves are engaged.

The worm wheel of mechanism 55-H operated by shaft 55 is fixedly connected to shaft 49 but not to the sleeve upon which the adjoining mechanism SS-AH, shown crosshatched, is mounted.

Arm 36-S is mounted on shaft 49 directly.

So when the clutch 54 is disengaged, operating either of shafts 55 or SS-A by rotation, causes shaft 49 to be rotated through the upper worm gear mechanism SS-H and thereby moves arm 36-S and link 35 which are operated from the shaft 49, all without movement of arm 36-F and link 45 to the flap.

When either shaft 55 or SS-A are turned by the controls with clutch 54 engaged, both worm gear mechanisms SS-H and SS-AH are operated simultaneously to move both levers 'S6-F and 36-8 and thereby operate link `45 to the ap and link 35 to the nose elements.

By installing on shaft 55 -a clutch similar to clutch 54, both the flap and nose elements or either one separately may be disengaged from the controls operating through shafts 55 or SS-A.

It is also foreseen that hydraulic means may be employed to operate these forward and/or rearward ele- -ments in a similar manner and relation through appropriate application and design of intake and release valves, feed and exhaust lines and other fluid control means and mechanisms.

In respect to applications of my invention for control -of the aircraft, 57 is the forward air entrance end of duct V58, that extends rearward to the tail surfaces. This duct as shown extends through the fuselage of the aircraft but it may also be situated in any other appropriate rearwardly extending member, such as a tail boom. This forward air entrance 57 is situated rearward of propeller 7 and in the flow path of the slipstream from propeller 7.

Gate 59 pivoted to the body structure at 60 serves to close duct entrance 57 during high speed flight, as in FIG. 2.

During slow speed or vertical flight, gate S9 swings forward and down in response to control action as in FIG. 1, thereby exposing open mouth 57 of duct 58 and allowing slipstream ow to enter and pass rearward through said duct to the stabilizer shroud-deflector combination identified here as stabilizer how-dispenser 61. This is vimmediately forward of the stabilizer leading edge and l to the control surfaces through booms or other suitable parts of the aircraft structure.

Gate 59 is operated through controls 64 in coordinated connection with the shroud, deflector and ap operating mechanism.

When high lift is desired for vertical orvsemi-vertical rising, descent or for slow landing without power, the shroud, deector and iiap are moved from closed positions, FIG. 2, to extended positions, FIG; l, through controls acting to turn control bracket 36. Gate 59 opens also through coordinated action of its controls 64. Then, for rising or descent, propeiler revolutions are increased to provide maximum slipstream effect and resulting airflow over the lifting and control surfaces.

For glide without power, high lift results from air flowing over these surfaces due to the forward motion of the aircraft `only-not from slipstream effect.

With the shroud, deflector, flap and air duct gate eX- tended, my invention increases wing lift and Ytail surface control in the following manner.

Airow entering the converging, venturi-like passageway between shroud 2 and deflector 3 builds up pressure at its entrance and then increases in velocity as it ows yrearward through said passageway and against the airfoil leading edge 65 between the vertical chordwise flow guide panels 8. Thus, by engaging and directing an unusually large volume of airiow against the airfoil leading edge, a ram effect is produced that builds up pressure v within the said passageway and forward of the leading edge 65.

This increased pressure drives airflow at high velocity out of the opening 66 between the shroud trailing edge and the upper surface of the leading edge and then back over the upper surface of the airfoil and flap between the vertical guide panels S and 9. This increase in ow volume and velocity over the airfoil or wing results in greater wing lift.

In conventional airplanes only a relatively small amount of the airow impinges on the airfoil or wing leading edge to build up nose kpressure for high velocity upper wing surface flow. However, the wide forward opening between the shroud 2 and deflector 3 leading edges engages a much larger volume of air and channels it against the airfoil or wing leading edge 65 under greater pressure than in cases of normal airfoils without a shroud and deector combination as embodied in this device.

This combination not only increases the ow volume and pressure against the wing leading edge but also increases the upward angle of the airflow at the wing nose to increase wing lift. The deflector airfoil member is largely responsible for this increase in the upward flow angle.

As the approaching ow impinges against the downwardly angled deflector 3, the flow in the passageway between the deector 3 and shroud 2 is deflected upward. Part of this flow passes out of the upper exit opening 66 over the airfoil nose at high velocityand part flows out through the lower exit opening 67 between deflector 3 and wing nose, at a lesser velocity. In arrangements of this device that omit the use of reflector 4, as in FIGS. 3 and 4, this lower ow passes rearward beneath the wing to the wing trailing edge or to the ap slot. Then part of this lower flow passes up through the slot to increase flap lift and part passes beneath the Hap.

The lower exit opening 67 between deiiector trailing edge and wing increases the iiow volume into the converging passageway formed `by shroud and gate, and greater flow velocity through the passageway with resulting increase in ow kinetic pressure at the wing leading edge by increase ow velocity into the forward opening between shroud 2 and deilector 3. The use of a dellector without an appreciable opening between the deector and wing nose will be effective to some degree but such an opening adds to the eifectiveness of this invention.

This opening 67 in conjunction with the rellector 4, FGS. 7, 8, 9 and l0, comprises a means to deect a column of air downward behind deflector 3 and beneath it, thereby resisting, retarding and defiecting upward in front of the dellector and over the wing, at least part of the airiiow which otherwise would pass immediately beneath the deilector 3 and thence rearward under the wing.

Thus this novel combination of passageway and rearward reflector 4 produces the erect of a much larger deflector 3 by deecting more of the airiiow upward and over the wing than otherwise would be the case.

The column of air deflected downward behind deiiector 3 by reflector 4 tends to retard the airflow beneath the wing and increase it over the wing in conformation with accepted rotary airtiow theory of airfoils.

The passageway 67 as shown in FTGS. 7, 8, 9 and l0 comprises a concave opening recess or indentation in the wing leading edge. The passageway need not assume this form however, when used in combination with reilector 4. lt may assume the form of the passageway shown in FlGS. 3 and 4 without any depression of the contours of the wing leading edge, with the reliector 4 rearward of this passageway in position to deiiect downward any air that passes rearward through said passageway.

Also, it is understood that this invention does not limit the smaller rearward reflector 4 to the design, form, size or structural arrangement shown in the igures. it aucipates any structure and/ or arrangement that functions to project a volume of air or other fluid medium downward behind and approximately parallel with any airfoil surface that extends downward from the leading edge of another associated airfoil.

Such a downward stream of air has the effect of enlarging and extending the said large deector 3 to the downward limits of the said downward stream because it forces the air upward in front of the deector that otherwise would pass beneath it and rearward.

Thus the downward lliow produced by any form of reilector 4 or by any air directing means, functions as a ellector in itself to a point below deflector 3 and provides the eiect of extending the material limits of the eiiector.

it is understood another form of reflector 4 might be hinged to retract within the contour limits of the wing and not remain in the air-stream beneath the wing when nose elements are retracted as illustrated in the figures.

Still another form of deector 3 would be jet streams projected downward like a gate to form a curtain of downwardly moving air or gas. This would have the same effect as a gate or deector of rigid material as shown.

in FIGS. 7, 8 and 9, the concave passageway 67 in the wing leading edge in combination with deflector 3 is shaped to provide a smooth iiow of air at maximum velocity while it also serves as a recess into which the deector Alits snugly where retracted, as in FIG. 10.

The upwardly increased angle of airliow approach at the wing leading edge due to the deector, increases the efective curvature of the wing and thereby wing lift. This, as well as increased flow volume and pressure that also increase wing lift, are improvements provided by this invention.

ln addition, greater wing lifting surface results when the shroud is extended. This, too, adds to the total wing lift. High lift is produced in this manner when airfoils, embodying this device, are disposed eectively in the slipstream ow of a propeller or other flow producing means, without forward motion of the aircraft.

Control surfaces also are simultaneously made effective by propeller slipstream iiow that enters the air duct entrance 57, passes rearward through duct 58, into dispenser 61 and out around the stabilizer 62 and elevons 63. Pressure on the control surfaces due to this ow produces pitching, nosing-up or rolling movements in accordance with appropriate angular deilections of the elevons 63. Flow through duct 58 may be provided alone or augmented by the impeller 63 driven by the engine 67 through driving means 69.

The preferred embodiment of the invention has been illustrated and described, but changes and modifications can be made, and some features can be used in dierent combinations without departing from the invention as deined in the claims.

What is claimed is:

l. in an aircraft wing, a combination of spanwise airfoil elements including a larger airfoil element and superimposed airfoil elements of shorter chord situated at least partially forward of said larger element and adjacent thereto; one of said forward elements being constituted entirely above and another below the most forward point of the leading Vedge of the larger airfoil element, at least one of the shorter chord elements or portions thereof being below the leading edge point of the larger airfoil element and being movable into retracted closed positions in relation to the forward portion of the more rearward larger airfoil element and into positions of extended spaced relation with each other and with the more rearward large airfoil element, the confronting faces of shorter elements converging toward the rear to produce a venturi effect, the shorter elements being shaped and located so as to constitute the leading edge of the wing when in retracted positions.

2. Combined in an aircraft, an airfoil, a rigid leading edge portion of said airfoil, other airfoils of smaller chord, situated in spaced relation with each other and more forward titan said rigid leading edge portion, at least one of which smaller airfoils is in spaced relation with the said rigid leading edge portion and entirely above the forwardly extended chord line of the more rearwardly situated larger airfoil; and at least one other of which is situated below the said chord line or its forward eXtension and inclined at a negative angle to a line tangent to the median line of the rigid airfoil at the leading edge point oi' said median line and at an angle that substantially retards the velocity of air flow below said rigid airfoil and directs at least part of said flow upward and over the leading edge of the rigid airfoil.

3. Combined in an aircraft, an airfoil, a portion of the under surface of the forward part of which is movable into a depressed position beneath the normal contour of said surface, control means for depressing said portion into the normal airflow path beneath the lower surface of said airfoil forward part and at a substantial negative angle and in position to retard air ow across said lower surface, and a portion of the upper surface including a leading edge of said airfoil which is movable to a raised extended position of spaced relation to the more rearward upper surface of the airfoil at a positive angle and in position to increase the velocity of air flow over the upper urface of the airfoil.

4. Combined in an aircraft; a surface which is depressed beneath the normal contour of the under surface into a position to retard air tlow across the lower surface of the airfoil and to deilect part of the approaching air-flow upward and forward of the leading edge of the said airfoil and over its upper surface; and a portion of the upper surface of said airfoil, including a leading edge thereof which is movable to a position of raised extended spaced relation to a tinted part of the said airfoil to increase the velocity of air iow over the upper surface of the air foil.

5. in an aircraft; a. spauwise airfoil comprising a rigid leading edge portion with a movable airfoil portion having a smaller chord than the spanwise airfoil and which is attached to the rigid leading edge portion; the airfoil portion of smaller chord constituting a portion of the acaaoev under surface of said rigid leading edge portion and being movable into a depressed position beneath the under surface of said spanwise airfoil and into spaced negative angular relation to the under surface of the rigid leading edge portion of said spanwise airfoil and in position to retard air llow across the lower surface of the airfoii, and control means for moving said portion having a smaller chord.

6. Combined in an aircraft airfoil; a rigid forward portion; an air deflector element, situated beneath the rigid forward portion and in extended, chordwise and negative angular relation to an under surface thereof; an opening between the deilector element and forward portion for a rearward ilow of gaseous matter through said opening and beneath the forward portion; an obstructing surface inclined in downward angular relation to the under surface of the rigid portion and below the normal contour thereof and in said rearward flow, and situated in the rearward pathway of said flow, behind said opening and rearward of the deilector element in position to deflect at least part of said rearward tlow downward behind and across a rearward surface of the detlector.

7. Combined in an aircraft airfoil; a rigid forward portion; an air deilector element, situated beneath the rigid forward portion and in extended, chordwise negative angular relation to an under surface thereof to provide an opening between the deilector element and forward portion for rearward llow of gaseous matter through said opening and beneath the forward portion; an obstructing reflector element inclined in downward angular relation to the under surface of the rigid portion and said rearward flow, and situated in the rearward pathway of said flow, behind said opening and rearward of the deflector element in position to deflect at least part of said rearward llow downward behind and adjacent to a rearward surface of the dellector, and control means for moving the deflector and reilector individually into both positions of parallel and angular relation to the under surface of the rigid portion.

8, Combined in an aircraft airfoil; a rigid forward portion; an air deilector element, situated beneath the rigid forward portion and in extended, chordwise negative angular relation to an under surface thereof to provide an opening between the deilector element and forward portion for rearward flow of gaseous matter through said opening and beneath the forward portion; an obstructing reector element inclined in downward angular relation to the under surface of the rigid portion and said rearward flow, and situated in the rearward pathway of said flow, behind said opening and rearward of the deflector element in position to deflect at least part of said rearward flow downward behind and adjacent to a rearward surface of the detlector, control means for moving both the deilector and reflector into both positions of parallel and of angular relation to the under surface of the rigid portion; and connection means coordinating the movements `of the delector and reflector into said positions in prescribed simultaneous relation to each other.

9. Combined in an aircraft airfoil; a rigid forward portion; a rearward portion hinged to said forward portion and which is movable into =positions of chordwise angular relation to the airfoil normal chord line; a smaller airfoil deilector element situated beneath the rigid forward portion and in extended chordwise negative angular relai2 positions of parallel and of angular relation to the under surface of the rigid portion; interconnection between said elements and movable rearward portion which coordinate all movements thereof in prescribed simultaneous re- 1ration `to one another.

10. In an aircraft airfoil; a deilecting means that directs a portion of the relative wind upwardly and rearwardly through a duct situated above the said deflecting means, all in combination with a reflecting means behind the deilecting means and set at a negative anglein position to direct said portion of the relative wind downward behind and along a rearward surface of the deilecting means; said dellecting means, duct and reflecting means being situated under a leading edge portion of the said airfoil of the aircraft.

ll. ln an aircraft airfoil; a deflecting means that directs a portion of the relative wind upward and rearwardly through a duct situated above the said dellecting means, all in combination with a reilecting means behind the dellecting means and set at a negative angle in position to direct said portion of the relative wind downward behind'and along a rearward surface ofthe dellecting means, said deilecting means, duct and reflecting means being situated under a leading edge portion of the said airfoil of the aircraft; the deilecting means being movable to a retracted position within the aircraft airfoil external contour, the reflecting means being movable simultaneously and in conjunction with the dellector, to a position of parallel relation to the under surface of the aircraft airfoil; and controls for moving said dellecting means and reflector element.

l2. Combined in an aircraft; an airfoil having a -rigid forward portion; an airfoil dellector element attached to and situated under the rigid forward position in spanwise parallel relation to it; a reflector element situated in spanwise parallel rearward spaced relation to the deflector element land under the rigid forward portion, with attachment thereto; both the airfoil deilector element and the reflector element being movable in conjunction with one another into positions of chordwise angular relation and into positions of chordwise parallel relation to an under surface of the forward rigid portion; where, in a position of said angular relation of the deflector element, an opening extends between a portion `of the dellector element and a surface portion of the aircraft airfoil above yit and which opening is substantially opposed and exposed to the direction of relative wind; and wherein the reflector element extends downwardly under the rigid forward portion, in negative angular relation to an under surface thereof, behind said opening in approximately parallel, spaced relation to the airfoil deilector element, and in position to deflect wind that passes across the upper end of the deflector element downward across the rearward surface thereof.

13. Combined in an aircraft; an airfoil having a rigid forward portion; an airfoil dellector element attached to and situated under the rigid forward portion in spanwise parallel relation to it; a rellector element in spanwise parallel rearward spaced relation to the deflector element and under the rigid forward poriton with attachment thereto; both deilector element and reflector element being movable in conjunction with one another into positions of chordwise negative angular relation to the airfoil and into positions of chordwise parallel relation to an undersurface of the forward rigid portion of the airfoil; where, in a position of said angular relation of the dellector element, an opening extends between a portion of the deilector element and a surface portion of the aircraft airfoil above it and which opening is substantially opposed and exposed to the direction of relative wind; and wherein the reflector element extends downwardly under vthe rigid forward portion in negative angular relation to passageway extends through said opening and between structures of the aircraft, from the forward surface of the airfoil defiector element to the rearward surface thereof; and through which a portion of the relative wind flows rearwardly, impinges upon the downwardly angled reilector element and is thereby deflected downwardly to the rear of and in contact with at least a portion of a rearward surface of the said airfoil detiector element.

14. In an aircraft airfoil; a spanwise element of the airfoil that extends downwardly under the leading edge portion of said airfoil yand with a forward surface exposed and opposed to the relative wind; a chordwise duct below a portion of the leading edge and above the spanwise element; said duct having -a forward entrance opening exposed to ow of relative wind from forward of the spanwise element, and a rearward exit opening rearward of said spanwise element;said forward opening, duct and rearward opening; providing for a flow of relative wind rearwardly, a downwardly andvnegatively angled surface situated behind said forward opening and said spanwise element, and upon which relative wind rearward ilow through said duct impinges and is deflected downwardly to the rear of and into a flow stream across and in contact with at least a portion of the rearward surface of the spanwise element.

15. Combined in an aircraft; an aircraft airfoil; smaller airfoil elements, situated adjacent to the leading edge portion of the aircraft airfoil in spanwise parallel and chordwise angular spaced relation thereto and to each other with confronting faces converging toward the rear to obtain a venturi effect; wherein a point of airflow separation at the leading edge of the aircraft airfoil is interposed between two of the airfoil elements at a location to increase the velocity of ow over the upper surface of the aircraft airfoil, the distance between the leading edges of the elements being greater than the maximum thickness of the aircraft airfoil, the smaller airfoil elements being movable toward and from said aircraft airfoil and being shaped to form the leading edge of the aircraft airfoil when moved toward said aircraft airfoil.

16. Combined in an aircraft; an aircraft airfoil; smaller airfoil elements, situated adjacent to the leading edge portion of the aircraft airfoil in spanwise parallel and chordwise angular spaced relation thereto and to each other with confronting faces converging toward the rear to obtain a venturi effect; wherein a point of airflow separation at the leading edge of the aircraft airfoil is interposed between two of the airfoil elements at a location to increase the velocity of ow over the upper surface of the aircraft airfoil; and the distance between leading edges of the two airfoil elements that are most remote from each other is greater than the distance between their trailing edges measured in the same chordwise plane, the smaller airfoil elements being movable toward and from said aircraft airfoil and being shaped to form the leading edge of the aircraft airfoil when moved toward said aircraft airfoil.

17. In an aircraft wing, a combination of spanwise airfoil elements including a larger airfoil element and superimposed airfoil elements of shorter chord situated at least partially forward of said larger element and adjacent thereto; one of said forward elements being situated at least partially above and another below the airflow separation point of the leading edge of the more rearward large airfoil element; at least two of said shorter elements or portions thereof being movable into retracted closed positions in relation to the forward portion of the more rearward larger airfoil element and into positions of extended spaced relation with each other and with the more rearward large airfoil element, the confronting faces of shorted elements converging toward the rear to produce a venturi effect, the shorter elements being shaped and located so as to constitute the leading edge of the wing when in retracted positions.

18. In an aircraft wing, a combination of spanwise airfoil elements including a larger airfoil element and superimposed airfoil elements of shorter chord situated at least partially forward of said larger element and adjacent thereto; one of said forward airfoil elements being situated at least partially above and another below the airow separation point of the leading edge of the more rearward large airfoil element; at least two of said smaller elements or portions thereof being movable into retracted closed positions in relation to the forward portion of the more rearward larger airfoil element and into positions of extended and forwardly diverging spaced relation with each other and with the more rearward large airfoil element, the distance between the leading edge of the uppermost said forward shorter chord element and the leading edge of the lowest said forward shorter chord element, when said elements are in maximum extended positions, being greater than the maximum thickness of the larger more rearward airfoil element in the same vertical chordwise plane, the confronting faces of the shorter elements converging toward the rear to produce a venturi effect, the shorter elements being shaped and located so as to constitute the leading edge of the wing when in retracted positions.

19. In an aircraft wing, a combination of spanwise airfoil elements including a larger airfoil element and superimposed airfoil elements of shorter chord situated at least partially forward of said larger element and adjacent thereto; one of said forward airfoil elements being situated at least partially above and another below the airow separation point of the leading edge of the more rearward large airfoil element; at least two of said smaller elements or portions thereof being movable by control operation into retracted closed position in relation to the forward ,portion of the more rearward larger airfoil element and into positions of extended and forwardly diverging spaced relation with each other and with the more rearward large airfoil element to produce a verturi effect; at least a portion of one of the shorter chord forward airfoil elements above the said airflow separation point being movable to change the angular relation between the said element and the larger more rearward airfoil element.

20. Combined in an aircraft; an airfoil, a portion of the under surface of the forward part of the airfoil being movable into a position depressed beneath the normal contour of said under surface and into the flow path of normal airow beneath the under surface of the airfoil forward part; and a portion of the upper surface of and including the leading edge of said airfoil being movable to a position of raised extended spaced relation to the upper surface of the more rearward portion of the airfoil; said portions when in extended positions diverging forwardly to obtain a venturi effect; and motion transmitting connections that move both portions in coordinated rela1v tion to one another.

21. The combination in an aircraft of propulsion means that project a stream of gaseous matter rearwardly, an airfoil having surfaces that form an opening with walls that converge rearwardly to form a passage for increasing the velocity of ilow of gaseous matter owing through said passage, the entrance of said opening being in position to receive the stream of gaseous matter from said propulsion means, and the opening being wider than the stream of gaseous matter so that said stream aspirates air into the opening from the ambient atmosphere adjacent to said stream, said opening having its discharge end in position to concentrate the stream and entrained air in a high Velocity flow over the upper surface of the airfoil to develop high lift on the airfoil when the craft is stationary.

22. The combination described in claim 21, and in which the opening in the airfoil is formed by two small airfoil elements constituted at least partially forward of the main part of the airfoil, the small airfoil elements being movable selectively between extended and retracted positions, said small elements forming the opening with walls that converge rearwardly when in extended position, and

asados? 15 said small elements being close to the'rest of the airfoil and within the streamline contour thereof when in retracted positions. i 23. The combination described in claim 22, and in which the` two small airfoil elements include an upper element and a lower element that constitute at least a part of the leading edge of the airfoil when they are in retracted positions.V

- 24; The combination described in claim 23, and in which the lower small airfoil element, when in extended position, extends downwardly at a negative angle to retard the ow of air under the main part of the airfoil.

V25. The combination described in claim 22, and in which the small airfoil elements include an upper element, and a lower element, each of which is movable independently of the flow, and separate control means for operating the different elements selectively or in coordinated relationship.

26. The combination described in claim 25, and in .Which at least oneof the small elements includes two parts on opposite sides of the longitudinal axis of the aircraft, control means for operating said parts independently of one another to vary the lift selectively on diierent sides of the longitudinal axis;

27. The combination described in claim 22, and in which there are two iins extending upwardly from the airfoil andina chordwise direction, the ns being spaced from one another spanwise and each iin being located in position to check tipwise flow of the stream of gaseous material Yand entrained air that is discharged over the upper surface'of the airfoil from said passage.

28. The combination described Vin claim 27, and in which the fins extend forward beyond the leading edge of the airfoil and into position to restrain spanwise ow of air at the entrance to said passage.

`References Cited in the iile of this patent UNITED STATES PATENTS 1,744,889 Hammons p Jan. 28, 1930 1,774,474 Burnelli Aug. 26, 1930 1,787,321 Orr Dec. 30, 1930 1,820,919 Massey Sept. 1, 1931 1,857,964 Leonard May l0, 1932 1,862,795 Mammen June 14, 1932 1,989,358 Guthier Jan. 29, 1935 2,066,336 Crouch Jan. 5, 1937 2,070,705 Barnhart Feb. 16, 1937 2,368,205 Diehl Jan. 30, 1945 2,420,323 Meyer 'May 13, 1947 2,552,073 Tindall May 8, 1951 FOREIGN PATENTS 542,269

France VMay 13, 1922 

